| Message ID | 20181119172536.52649-12-mimu@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: s390: make use of the GIB | expand |
On Mon, Nov 19, 2018 at 06:25:35PM +0100, Michael Mueller wrote: > @@ -3521,6 +3523,10 @@ static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason) > vcpu->run->s.regs.gprs[15] = vcpu->arch.sie_block->gg15; > > atomic_dec(&vcpu->kvm->arch.vcpus_in_sie); > + if (vcpu->kvm->arch.gib_in_use && > + !in_alert_list(vcpu->kvm->arch.gisa) && > + !atomic_fetch_andnot(0, &vcpu->kvm->arch.vcpus_in_sie)) > + vcpu->kvm->arch.gisa->iam = vcpu->kvm->arch.iam; This looks a bit odd to me. Why not simply !atomic_read(&vcpu->kvm->arch.vcpus_in_sie)) instead of the atomic_fetch_andnot() construct? Did I miss something?
On 19.11.18 20:38, Heiko Carstens wrote: > On Mon, Nov 19, 2018 at 06:25:35PM +0100, Michael Mueller wrote: >> @@ -3521,6 +3523,10 @@ static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason) >> vcpu->run->s.regs.gprs[15] = vcpu->arch.sie_block->gg15; >> >> atomic_dec(&vcpu->kvm->arch.vcpus_in_sie); >> + if (vcpu->kvm->arch.gib_in_use && >> + !in_alert_list(vcpu->kvm->arch.gisa) && >> + !atomic_fetch_andnot(0, &vcpu->kvm->arch.vcpus_in_sie)) >> + vcpu->kvm->arch.gisa->iam = vcpu->kvm->arch.iam; > > This looks a bit odd to me. Why not simply > !atomic_read(&vcpu->kvm->arch.vcpus_in_sie)) > instead of the atomic_fetch_andnot() construct? > > Did I miss something? > No trick under the covers here. The atomic_read() will do the job.
On Mon, 19 Nov 2018 18:25:35 +0100 Michael Mueller <mimu@linux.ibm.com> wrote: > The patch implements a handler for GIB alert interruptions > on the host. Its task is to alert storage backed guests that > interrupts are pending for them. > > A GIB alert interrupt statistic counter is added as well: > > $ cat /proc/interrupts > CPU0 CPU1 > ... > GAL: 0 0 [I/O] GIB Alert > ... > > Signed-off-by: Michael Mueller <mimu@linux.ibm.com> > --- > arch/s390/include/asm/irq.h | 1 + > arch/s390/include/asm/isc.h | 1 + > arch/s390/kernel/irq.c | 1 + > arch/s390/kvm/interrupt.c | 57 +++++++++++++++++++++++++++++++++++++-------- > arch/s390/kvm/kvm-s390.c | 6 +++++ > arch/s390/kvm/kvm-s390.h | 5 ++++ > 6 files changed, 61 insertions(+), 10 deletions(-) > @@ -2919,7 +2920,7 @@ static void nullify_gisa(struct kvm_s390_gisa *gisa) > * belongs to. Thus, the pending guest interruption will be processed > * in SIE context. > */ > -static void __maybe_unused process_gib_alert_list(void) > +static void process_gib_alert_list(void) Can't you merge the patch creating that function into this patch, so you don't need to add __maybe_unused in the first place? (I don't think the function is big enough to need separate review.) > { > struct kvm_s390_gisa *gisa = unlink_gib_alert_list(); > struct kvm_s390_gisa *next_alert;
On 26.11.18 17:35, Cornelia Huck wrote: > On Mon, 19 Nov 2018 18:25:35 +0100 > Michael Mueller <mimu@linux.ibm.com> wrote: > >> The patch implements a handler for GIB alert interruptions >> on the host. Its task is to alert storage backed guests that >> interrupts are pending for them. >> >> A GIB alert interrupt statistic counter is added as well: >> >> $ cat /proc/interrupts >> CPU0 CPU1 >> ... >> GAL: 0 0 [I/O] GIB Alert >> ... >> >> Signed-off-by: Michael Mueller <mimu@linux.ibm.com> >> --- >> arch/s390/include/asm/irq.h | 1 + >> arch/s390/include/asm/isc.h | 1 + >> arch/s390/kernel/irq.c | 1 + >> arch/s390/kvm/interrupt.c | 57 +++++++++++++++++++++++++++++++++++++-------- >> arch/s390/kvm/kvm-s390.c | 6 +++++ >> arch/s390/kvm/kvm-s390.h | 5 ++++ >> 6 files changed, 61 insertions(+), 10 deletions(-) > >> @@ -2919,7 +2920,7 @@ static void nullify_gisa(struct kvm_s390_gisa *gisa) >> * belongs to. Thus, the pending guest interruption will be processed >> * in SIE context. >> */ >> -static void __maybe_unused process_gib_alert_list(void) >> +static void process_gib_alert_list(void) > > Can't you merge the patch creating that function into this patch, so > you don't need to add __maybe_unused in the first place? (I don't think > the function is big enough to need separate review.) The function has been rewritten for v3 and I consider it worth to stay separated now. The version is already in the starting blocks and was just delayed by all your replies. ;) > >> { >> struct kvm_s390_gisa *gisa = unlink_gib_alert_list(); >> struct kvm_s390_gisa *next_alert; >
diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h index 2f7f27e5493f..afaf5e3c57fd 100644 --- a/arch/s390/include/asm/irq.h +++ b/arch/s390/include/asm/irq.h @@ -62,6 +62,7 @@ enum interruption_class { IRQIO_MSI, IRQIO_VIR, IRQIO_VAI, + IRQIO_GAL, NMI_NMI, CPU_RST, NR_ARCH_IRQS diff --git a/arch/s390/include/asm/isc.h b/arch/s390/include/asm/isc.h index 6cb9e2ed05b6..b2cc1ec78d06 100644 --- a/arch/s390/include/asm/isc.h +++ b/arch/s390/include/asm/isc.h @@ -21,6 +21,7 @@ /* Adapter interrupts. */ #define QDIO_AIRQ_ISC IO_SCH_ISC /* I/O subchannel in qdio mode */ #define PCI_ISC 2 /* PCI I/O subchannels */ +#define GAL_ISC 5 /* GIB alert */ #define AP_ISC 6 /* adjunct processor (crypto) devices */ /* Functions for registration of I/O interruption subclasses */ diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c index 0e8d68bac82c..0cd5a5f96729 100644 --- a/arch/s390/kernel/irq.c +++ b/arch/s390/kernel/irq.c @@ -88,6 +88,7 @@ static const struct irq_class irqclass_sub_desc[] = { {.irq = IRQIO_MSI, .name = "MSI", .desc = "[I/O] MSI Interrupt" }, {.irq = IRQIO_VIR, .name = "VIR", .desc = "[I/O] Virtual I/O Devices"}, {.irq = IRQIO_VAI, .name = "VAI", .desc = "[I/O] Virtual I/O Devices AI"}, + {.irq = IRQIO_GAL, .name = "GAL", .desc = "[I/O] GIB Alert"}, {.irq = NMI_NMI, .name = "NMI", .desc = "[NMI] Machine Check"}, {.irq = CPU_RST, .name = "RST", .desc = "[CPU] CPU Restart"}, }; diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 40878efbd5cd..240b58b67f18 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -23,6 +23,7 @@ #include <asm/gmap.h> #include <asm/switch_to.h> #include <asm/nmi.h> +#include <asm/airq.h> #include "kvm-s390.h" #include "gaccess.h" #include "trace-s390.h" @@ -2890,7 +2891,7 @@ int kvm_s390_get_irq_state(struct kvm_vcpu *vcpu, __u8 __user *buf, int len) return n; } -static struct kvm_s390_gisa __maybe_unused *unlink_gib_alert_list(void) +static struct kvm_s390_gisa *unlink_gib_alert_list(void) { u32 gisa; @@ -2919,7 +2920,7 @@ static void nullify_gisa(struct kvm_s390_gisa *gisa) * belongs to. Thus, the pending guest interruption will be processed * in SIE context. */ -static void __maybe_unused process_gib_alert_list(void) +static void process_gib_alert_list(void) { struct kvm_s390_gisa *gisa = unlink_gib_alert_list(); struct kvm_s390_gisa *next_alert; @@ -2941,6 +2942,9 @@ static void __maybe_unused process_gib_alert_list(void) void kvm_s390_gisa_clear(struct kvm *kvm) { if (kvm->arch.gisa) { + kvm->arch.gisa->iam = 0; + while (in_alert_list(kvm->arch.gisa)) + process_gib_alert_list(); nullify_gisa(kvm->arch.gisa); VM_EVENT(kvm, 3, "gisa 0x%pK cleared", kvm->arch.gisa); } @@ -2952,9 +2956,9 @@ void kvm_s390_gisa_init(struct kvm *kvm) kvm->arch.gisa = &kvm->arch.sie_page2->gisa; kvm->arch.iam = 0; spin_lock_init(&kvm->arch.iam_ref_lock); - VM_EVENT(kvm, 3, "gisa 0x%pK initialized", kvm->arch.gisa); - kvm_s390_gisa_clear(kvm); + nullify_gisa(kvm->arch.gisa); kvm->arch.gib_in_use = !!gib; + VM_EVENT(kvm, 3, "gisa 0x%pK initialized", kvm->arch.gisa); } } @@ -2962,6 +2966,10 @@ void kvm_s390_gisa_destroy(struct kvm *kvm) { if (!kvm->arch.gisa) return; + + kvm->arch.gisa->iam = 0; + while (in_alert_list(kvm->arch.gisa)) + process_gib_alert_list(); kvm->arch.gisa = NULL; kvm->arch.iam = 0; } @@ -3007,36 +3015,65 @@ int kvm_s390_gisc_unregister(struct kvm *kvm, u32 gisc) } EXPORT_SYMBOL_GPL(kvm_s390_gisc_unregister); +static void gib_alert_irq_handler(struct airq_struct *airq) +{ + inc_irq_stat(IRQIO_GAL); + process_gib_alert_list(); +} + +static struct airq_struct gib_alert_irq = { + .handler = gib_alert_irq_handler, + .lsi_ptr = &gib_alert_irq.lsi_mask, +}; + void kvm_s390_gib_destroy(void) { if (!gib) return; chsc_sgib(0); + unregister_adapter_interrupt(&gib_alert_irq); free_page((unsigned long)gib); gib = NULL; } int kvm_s390_gib_init(u8 nisc) { + int rc = 0; + if (!css_general_characteristics.aiv) { KVM_EVENT(3, "%s", "gib not initialized, no AIV facility"); - return 0; + goto out; } gib = (struct kvm_s390_gib *)get_zeroed_page(GFP_KERNEL | GFP_DMA); if (!gib) { KVM_EVENT(3, "gib 0x%pK memory allocation failed", gib); - return -ENOMEM; + rc = -ENOMEM; + goto out; + } + + gib_alert_irq.isc = nisc; + if (register_adapter_interrupt(&gib_alert_irq)) { + KVM_EVENT(3, "gib 0x%pK GAI registration failed", gib); + rc = -EIO; + goto out_free; } gib->nisc = nisc; if (chsc_sgib((u32)(u64)gib)) { KVM_EVENT(3, "gib 0x%pK AIV association failed", gib); - free_page((unsigned long)gib); - gib = NULL; - return -EIO; + rc = -EIO; + goto out_unreg; } KVM_EVENT(3, "gib 0x%pK (nisc=%d) initialized", gib, gib->nisc); - return 0; + return rc; + +out_unreg: + unregister_adapter_interrupt(&gib_alert_irq); +out_free: + free_page((unsigned long)gib); + gib = NULL; +out: + return rc; } diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index d55de44df135..386f98029a3f 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -3460,6 +3460,8 @@ static int vcpu_pre_run(struct kvm_vcpu *vcpu) } atomic_inc(&vcpu->kvm->arch.vcpus_in_sie); + if (vcpu->kvm->arch.gib_in_use) + vcpu->kvm->arch.gisa->iam = 0; vcpu->arch.sie_block->icptcode = 0; cpuflags = atomic_read(&vcpu->arch.sie_block->cpuflags); @@ -3521,6 +3523,10 @@ static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason) vcpu->run->s.regs.gprs[15] = vcpu->arch.sie_block->gg15; atomic_dec(&vcpu->kvm->arch.vcpus_in_sie); + if (vcpu->kvm->arch.gib_in_use && + !in_alert_list(vcpu->kvm->arch.gisa) && + !atomic_fetch_andnot(0, &vcpu->kvm->arch.vcpus_in_sie)) + vcpu->kvm->arch.gisa->iam = vcpu->kvm->arch.iam; if (exit_reason == -EINTR) { VCPU_EVENT(vcpu, 3, "%s", "machine check"); diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 1a79105b0e9f..1c93ceaeb9e4 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -196,6 +196,11 @@ static inline int kvm_s390_user_cpu_state_ctrl(struct kvm *kvm) return kvm->arch.user_cpu_state_ctrl != 0; } +static inline bool in_alert_list(struct kvm_s390_gisa *gisa) +{ + return (u32)(u64)gisa != gisa->next_alert; +} + /* implemented in interrupt.c */ int kvm_s390_handle_wait(struct kvm_vcpu *vcpu); void kvm_s390_vcpu_wakeup(struct kvm_vcpu *vcpu);
The patch implements a handler for GIB alert interruptions on the host. Its task is to alert storage backed guests that interrupts are pending for them. A GIB alert interrupt statistic counter is added as well: $ cat /proc/interrupts CPU0 CPU1 ... GAL: 0 0 [I/O] GIB Alert ... Signed-off-by: Michael Mueller <mimu@linux.ibm.com> --- arch/s390/include/asm/irq.h | 1 + arch/s390/include/asm/isc.h | 1 + arch/s390/kernel/irq.c | 1 + arch/s390/kvm/interrupt.c | 57 +++++++++++++++++++++++++++++++++++++-------- arch/s390/kvm/kvm-s390.c | 6 +++++ arch/s390/kvm/kvm-s390.h | 5 ++++ 6 files changed, 61 insertions(+), 10 deletions(-)